title: Does increased sunlight exposure work as a strategy to improve vitamin D status in the elderly: a cluster randomised controlled trial.
abstract: CONCLUSIONS
  Sunlight exposure by improving vitamin D status could be a simple public health strategy in reducing falls among frail elder people. In a randomised controlled trial, adherence to sunlight exposure was low (median adherence, 26%) and no effect of increased UV exposure on falls risk was observed (incidence rate ratio (IRR) 1.06, P = 0.73).
  
  
  BACKGROUND
  This study aimed to determine whether increased sunlight exposure was effective to improve vitamin D status and reduce falls in the elderly.
  
  
  METHODS
  In a cluster randomised controlled trial (NCT00322166 at ClinicalTrials.gov), 602 residents aged 70 or more (mean age, 86.4 years; 71% female) were recruited from 51 aged care facilities in Northern Sydney, Australia. Participants were randomised by facility to receive either increased sunlight exposure (additional 30-40 min/day in the early morning) with (UV+) or without (UV) calcium supplementation (600 mg/day) or neither (control) for a year. The co-primary endpoints were change in serum 25 hydroxy vitamin D (25OHD) and falls incidence after 12 months.
  
  
  RESULTS
  Adherence to sunlight exposure was low (median adherence, 26%; IQR, 7%-45%). Serum 25OHD levels were low at baseline (median, 32.9 nmol/L) and increased only slightly depending on the number of sunlight sessions attended over 12 months (P = 0.04). During the study, 327 falls occurred in 111 (54%) subjects in the control group, 326 falls in 111 (58%) subjects in the UV only group and 335 falls in 108 (52%) subjects in the UV+ group. By intention-to-treat analysis, there was no significant effect of increased UV exposure on falls risk (IRR, 1.06; 95% CI, 0.76-1.48; P = 0.73). However, in 66 participants who attended ≥130 sessions per year (adherence, ≥50% of 260 sessions-five per week), falls were significantly reduced (IRR, 0.52; 95% CI, 0.31-0.88; P = 0.01) compared with the control group.
  
  
  CONCLUSIONS
  Increased sunlight exposure did not reduce vitamin D deficiency or falls risk in frail older people. This public health strategy was not effective most likely due to poor adherence to the intervention.
authors.affiliation: Institute of Bone and Joint Research, University of Sydney, Sydney, Australia. sambrook@med.usyd.edu.au
authors.forename: P N
authors.initials: PN
authors.lastname: Sambrook
authors.forename: I D
authors.initials: ID
authors.lastname: Cameron
authors.forename: J S
authors.initials: JS
authors.lastname: Chen
authors.forename: R G
authors.initials: RG
authors.lastname: Cumming
authors.forename: S
authors.initials: S
authors.lastname: Durvasula
authors.forename: M
authors.initials: M
authors.lastname: Herrmann
authors.forename: C
authors.initials: C
authors.lastname: Kok
authors.forename: S R
authors.initials: SR
authors.lastname: Lord
authors.forename: M
authors.initials: M
authors.lastname: Macara
authors.forename: L M
authors.initials: LM
authors.lastname: March
authors.forename: R S
authors.initials: RS
authors.lastname: Mason
authors.forename: M J
authors.initials: MJ
authors.lastname: Seibel
authors.forename: N
authors.initials: N
authors.lastname: Wilson
authors.forename: J M
authors.initials: JM
authors.lastname: Simpson
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000368:Aged; D000369:Aged, 80 and over; D002119:Calcium Carbonate / Q000627:therapeutic use; D019587:Dietary Supplements; D005260:Female; D050723:Fractures, Bone / Q000517:prevention & control; D006370:Heliotherapy / Q000009:adverse effects / Q000379:methods* / Q000523:psychology; D006707:Homes for the Aged; D006801:Humans; D008297:Male; D010349:Patient Compliance / Q000706:statistics & numerical data; D016896:Treatment Outcome; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000628:therapy*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002119:Calcium Carbonate